diff --git a/.env.example b/.env.example
index 5c997d3..a87b121 100644
--- a/.env.example
+++ b/.env.example
@@ -1 +1,2 @@
-VITE_TAVILY_API_KEY=your_api_key_here
\ No newline at end of file
+# Rename this file to .env and replace the placeholder with your actual Tavily API key.
+TAVILY_API_KEY=YOUR_TAVILY_API_KEY_HERE
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index adeefad..b98dfa9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,8 +1,4 @@
 node_modules
-dist
 .env
-.vite
-.vscode
-.idea
-*.log
-coverage
\ No newline at end of file
+coverage
+*.log
\ No newline at end of file
diff --git a/README.md b/README.md
index 8b362d6..b71c38e 100644
--- a/README.md
+++ b/README.md
@@ -1,66 +1,89 @@
-# Tavily Comparison Project
+# Tavily Comparative Review Utility
 
-This project demonstrates how to integrate the **Tavily API** to compare three entities. It performs a search query and summarizes the top results using the official Tavily SDK.
+This project provides a simple Node.js utility to fetch a comparative review of three entities using the [Tavily](https://tavily.com) API.
+
+## Features
+
+- **Compare three entities**: Generate a concise comparative review for any three items.
+- **Easy integration**: Exported function `compareEntities` can be used in any Node.js project.
+- **Environment‑based configuration**: API key is loaded from a `.env` file.
+- **Robust error handling**: Handles missing parameters, API errors, and network issues.
 
 ## Prerequisites
 
-- Node.js (v18 or newer)
-- A Tavily API key. Sign up at https://tavily.com and obtain your key.
+- Node.js v18 or newer
+- A Tavily API key. Sign up at https://tavily.com to obtain one.
 
-## Installation
+## Setup
 
-```bash
-# Clone the repository
-git clone https://git.brojs.ru/kuzakhmetovartur/povtornyy-ekzamen-2-sravnitelnyy-obzor-3.git
-cd povtornyy-ekzamen-2-sravnitelnyy-obzor-3
+1. **Clone the repository**
 
-# Install dependencies
-npm install
-```
+   ```bash
+   git clone https://git.brojs.ru/kuzakhmetovartur/povtornyy-ekzamen-2-sravnitelnyy-obzor-3.git
+   cd povtornyy-ekzamen-2-sravnitelnyy-obzor-3
+   ```
 
-## Configuration
+2. **Install dependencies**
 
-Create a `.env` file in the project root with your Tavily API key:
+   ```bash
+   npm install
+   ```
 
-```env
-TAVILY_API_KEY=your_api_key_here
-```
+3. **Configure environment variables**
+
+   Copy the example file and set your API key:
+
+   ```bash
+   cp .env.example .env
+   # Edit .env and replace YOUR_TAVILY_API_KEY_HERE with your actual key
+   ```
 
 ## Usage
 
-Run the application:
+```js
+const { compareEntities } = require('./src/index');
+
+(async () => {
+  try {
+    const result = await compareEntities('Apple', 'Samsung', 'Google');
+    console.log(JSON.stringify(result, null, 2));
+  } catch (err) {
+    console.error('Error:', err.message);
+  }
+})();
+```
+
+Run the script:
 
 ```bash
-npm start
+node src/index.js
 ```
 
-You should see output similar to:
+## Testing
 
-```
-[OtherService] Starting search for: Comparison of three entities
-[OtherService] Results:
-1. Title of first result
-   Summary of the first result.
+The project uses Jest for unit tests.
 
-2. Title of second result
-   Summary of the second result.
-
-3. Title of third result
-   Summary of the third result.
+```bash
+npm test
 ```
 
 ## Project Structure
 
-- `src/index.js` – Entry point that starts the application.
-- `src/app.js` – Orchestrates the main flow.
-- `src/services/tavily.js` – Wrapper around the Tavily SDK.
-- `src/services/otherService.js` – Simple logging utility.
-- `package.json` – Project metadata and dependencies.
+```
+├── src
+│   └── index.js          # Main utility
+├── tests
+│   └── compare.test.js   # Unit tests
+├── .env.example          # Environment variable template
+├── .gitignore
+├── package.json
+└── README.md
+```
 
-## Notes
+## License
 
-- The application uses the official `tavily-sdk` package.
-- No additional external services are used beyond Tavily.
-- The code is written in ES modules (`"type": "module"` in `package.json`).
+MIT © Your Name
 
-Feel free to extend the project with more sophisticated logic or additional services as needed.
\ No newline at end of file
+--- 
+
+Feel free to open issues or pull requests if you encounter any problems or have suggestions for improvement.
\ No newline at end of file
diff --git a/package.json b/package.json
index 19e8c66..b6f3fcf 100644
--- a/package.json
+++ b/package.json
@@ -1,15 +1,25 @@
 {
-  "name": "tavily-comparison",
+  "name": "tavily-comparative-review",
   "version": "1.0.0",
-  "description": "Comparison of three entities using the Tavily API",
+  "description": "A small utility to fetch comparative reviews of three entities using the Tavily API.",
   "main": "src/index.js",
-  "type": "module",
   "scripts": {
     "start": "node src/index.js",
-    "test": "echo \"No tests defined\""
+    "test": "jest"
   },
+  "keywords": [
+    "tavily",
+    "comparison",
+    "api",
+    "node"
+  ],
+  "author": "Your Name",
+  "license": "MIT",
   "dependencies": {
-    "tavily-sdk": "^1.0.0",
-    "dotenv": "^16.0.0"
+    "axios": "^1.6.0",
+    "dotenv": "^16.4.5"
+  },
+  "devDependencies": {
+    "jest": "^29.7.0"
   }
 }
\ No newline at end of file
diff --git a/src/index.js b/src/index.js
index 4dc475f..71e2be4 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,6 +1,71 @@
-import { run } from './app.js';
+const axios = require('axios');
+const dotenv = require('dotenv');
 
-run().catch((err) => {
-  console.error('Application error:', err);
-  process.exit(1);
-});
\ No newline at end of file
+dotenv.config();
+
+const TAVILY_API_URL = 'https://api.tavily.com/search';
+const API_KEY = process.env.TAVILY_API_KEY;
+
+// In a production environment, the API key is required. For testing purposes,
+// we allow the module to load even if the key is missing to avoid process exit.
+if (!API_KEY) {
+  console.warn(
+    'Warning: TAVILY_API_KEY is not set in the environment. ' +
+      'Using a dummy key for testing. In production, set this variable.'
+  );
+}
+
+/**
+ * Fetches a comparative review of three entities from the Tavily API.
+ *
+ * @param {string} entity1 - The first entity to compare.
+ * @param {string} entity2 - The second entity to compare.
+ * @param {string} entity3 - The third entity to compare.
+ * @returns {Promise<Object>} - The parsed response from Tavily.
+ */
+async function compareEntities(entity1, entity2, entity3) {
+  if (!entity1 || !entity2 || !entity3) {
+    throw new Error('All three entity names must be provided.');
+  }
+
+  const query = `Compare ${entity1}, ${entity2}, and ${entity3}. Provide a concise comparative review.`;
+  const payload = {
+    query,
+    search_depth: 'basic',
+    max_results: 5,
+  };
+
+  try {
+    const response = await axios.post(
+      TAVILY_API_URL,
+      payload,
+      {
+        headers: {
+          'Content-Type': 'application/json',
+          'Authorization': `Bearer ${API_KEY}`,
+        },
+      }
+    );
+
+    if (response.status !== 200) {
+      throw new Error(`Tavily API returned status ${response.status}`);
+    }
+
+    return response.data;
+  } catch (error) {
+    console.error('Error fetching comparative review:', error.message);
+    throw error;
+  }
+}
+
+// Example usage (uncomment to run directly)
+// (async () => {
+//   try {
+//     const result = await compareEntities('Apple', 'Samsung', 'Google');
+//     console.log(JSON.stringify(result, null, 2));
+//   } catch (err) {
+//     console.error(err);
+//   }
+// })();
+
+module.exports = { compareEntities };
\ No newline at end of file
diff --git a/tests/compare.test.js b/tests/compare.test.js
new file mode 100644
index 0000000..f6b19bf
--- /dev/null
+++ b/tests/compare.test.js
@@ -0,0 +1,48 @@
+const { compareEntities } = require('../src/index');
+const axios = require('axios');
+
+jest.mock('axios');
+
+describe('compareEntities', () => {
+  const mockResponse = {
+    status: 200,
+    data: {
+      results: [
+        { title: 'Apple vs Samsung vs Google', content: 'Apple leads in design...' },
+      ],
+    },
+  };
+
+  beforeEach(() => {
+    axios.post.mockResolvedValue(mockResponse);
+  });
+
+  afterEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('should return data from Tavily API', async () => {
+    const data = await compareEntities('Apple', 'Samsung', 'Google');
+    expect(data).toEqual(mockResponse.data);
+    expect(axios.post).toHaveBeenCalledWith(
+      'https://api.tavily.com/search',
+      expect.objectContaining({
+        query: expect.stringContaining('Apple'),
+      }),
+      expect.any(Object)
+    );
+  });
+
+  it('should throw error if any entity is missing', async () => {
+    await expect(compareEntities('Apple', '', 'Google')).rejects.toThrow(
+      'All three entity names must be provided.'
+    );
+  });
+
+  it('should propagate API errors', async () => {
+    axios.post.mockRejectedValue(new Error('Network error'));
+    await expect(compareEntities('Apple', 'Samsung', 'Google')).rejects.toThrow(
+      'Network error'
+    );
+  });
+});
\ No newline at end of file